I use Porcelin on the tube before I save it, then I use Optimization prior to saving it as a gif. The problem is you are saving a photographic image that has 16 million colours and saving it as a gif saves it in 256 colours so it is removing 15Millon+ colours from your image and that is why she looks like that. You will get some degradation, but can minimise it to some extent by fiddling with the Optimization settings.